title: Mediating effect of executive function on memory in normal aging adults.
abstract: OBJECTIVE
  We hypothesize that the effect of aging on memory is mediated by executive function.
  
  
  METHODS
  Two hundred and thirty healthy adults (101 male, 129 female) were recruited for the study. We used a promising, newly developed, computerized neuropsychological test for the measurement of executive function and memory. The data were analyzed using structural equation modeling and path analysis.
  
  
  RESULTS
  The full mediation model showed a good fit to the data. However, chi-squared (χ(2)) tests for model comparison indicated that the partial mediation model better fits our data. Thus, the partial mediation model was used as the final model. In terms of auditory-verbal memory, the effect of aging on memory was fully mediated by executive function. However, visuo-spatial memory was significantly affected both indirectly (through executive function) and directly (by aging). Gender differences were not significant in this model.
  
  
  CONCLUSIONS
  This study demonstrated the importance of executive function in the memory functioning of normal aging adults. It is noteworthy that modality differences were found between auditory-verbal and visuo-spatial memory. Aging is not the only factor that drives memory decline, and its direct, adverse effect on memory was more prominent in the visuo-spatial memory task than auditory-verbal memory task. Since performance in both modalities is fully or partially mediated by executive function, it is important to train normal aging adults in executive control skills, such as planning, strategy formation, and rapid decision making.
authors.affiliation: Department of Child and Adolescent Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Min-Jae
authors.initials: MJ
authors.lastname: Kim
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
authors.forename: Min-Sup
authors.initials: MS
authors.lastname: Shin
keywords: Aging; Executive function; Memory; Neuropsychological test; Trail making test